1. Field of the Invention
The present invention relates to a lamp assembly, a backlight assembly and a liquid crystal display (LCD) apparatus having the same, and more particularly to a lamp assembly to enhance dark portion generated by electrodes of a lamp in the lamp assembly, to a backlight assembly and a liquid crystal display (LCD) apparatus having the same.
2. Description of the Related Art
LCD apparatuses display image by reflecting external light transmitted through a LCD panel or by using a light source, i.e. a backlight assembly, disposed on the rear surface of the LCD panel, instead of generating light by itself.
The backlight assembly includes a lamp for generating light, a light guiding plate for guiding the light generated from the lamp toward the LCD panel, a reflection plate (or a reflector) disposed under the light guiding plate to reflect the light leaked from the light guiding plate toward the light guiding plate, and optical sheets for enhancing brightness of the light transmitted from the light guiding plate.
The light guiding plate of the backlight assembly has a flat type backlight assembly and a wedge type backlight assembly according as the position of the lamps concerning the light guiding plate. The lamps are disposed at both end portions of the light guiding plate in the flat type backlight assembly, and lamps are disposed at one end portion of the light guiding plate in the flat type backlight assembly.
FIG. 1 is a cross-sectional view showing a conventional flat type backlight assembly.
Referring to FIG. 1, lamp receiving containers (or lamp reflectors) 12a and 12b are disposed at both ends of the light guiding plate 10, and prevent leakage of the light generated by lamps 14a and 14b. The lamps 14a and 14b are disposed inside of the lamp receiving containers 12a and 12b, and generate light. The light guiding plate 10 receives light from the lamps 14a and 14b and guides the light toward a diffusion sheet 16. A reflection plate 18 is disposed on the lower surface of the light guiding plate 10, and reflects the light leaked from the lower surface of the light guiding plate 10 toward the light guiding plate 10. The light guiding plate 10 in the backlight assembly is made of a high polymer such as Polymethyl Methacrylate (PMMA) or Cyclic Olefin Polymer (COP), to thereby have a high density. Accordingly, the light guiding plate is the heaviest one of all elements in the LCD module. The wedge type light guiding plate is used in the LCD of notebook computer more usually than the flat type light guiding plate because the notebook computer needs a lighter and thinner LCD.
FIG. 2 is a cross-sectional view showing a conventional wedge type backlight assembly.
Referring to FIG. 2, a lamp receiving container (or a lamp reflector) 22 is disposed at one end of a light guiding plate 20, and prevents leakage of the light generated by a lamp 24. The lamp 24 is disposed inside of the lamp receiving container 22, and generates light. The light guiding plate 20 receives light from the lamp 24 and guides the light toward a diffusion sheet 26. A reflection plate 28 is disposed on the lower surface of the light guiding plate 20, and reflects the light leaked from the lower surface of the light guiding plate 20 toward the light guiding plate 20.
FIG. 3 is a schematic view showing effective and non-effective luminous areas of a conventional backlight assembly.
Referring to FIG. 3, since a lamp holder not only supports a lamp but also prevents fluctuation of a light guiding plate, when the light guiding plate is pushed in a Y-direction by external impulse and vibration, the lamp holder is disposed adjacent to an effective display area (or active area) that is bounded by the dotted line 301. Accordingly, this causes dark portions, which are formed at portions of the LCD panel corresponding to electrodes of the lamp, to deteriorate displaying quality.
A non-effective emitting area of the lamp is extended to the effective display area, to thereby overlap with the effective display area due to the limited space of the backlight assembly when disposing the lamp in the backlight assembly. This is a main reason to cause the dark portions.
There are some approaches to reduce the dart portions. One approach reduces the length of the non-effective emitting area of the lamp by shortening the length of the electrodes of the lamp. Another approach forms predetermined patterns to change the path of the light incident from the lamp on the lower surface of the light guiding plate, especially on the lower surface adjacent to a corner portion of the light guiding plate, so as to change the path of the light incident from the lamp. However, these approaches cannot reduce the dark portion when the width of the LCD module decreases.
The present invention provides a lamp assembly for enhancing the brightness of light by reducing the dark portions corresponding to the electrodes of a lamp.
The present invention further provides a backlight assembly having a lamp assembly capable of enhancing light brightness by reducing dark portions in the lamp assembly.
The present invention further provides an LCD apparatus having a backlight assembly capable of reducing dark portions in the backlight assembly to enhance light brightness.
In one aspect of the invention, a lamp assembly comprises a lamp comprising a first electrode, disposed on a first end of the lamp, for receiving a first electric power, and a second electrode, disposed on a second end of the lamp, for receiving a second electric power, the lamp emitting a light in response to the first and second electric power, and a lamp holder for receiving the first end or the second end of the lamp and for emitting the light.
In another aspect, a backlight assembly comprises a lamp assembly comprising a lamp emitting a first light and a lamp holder for receiving one end of the lamp, the lamp holder receiving the first light emitted from the lamp to emit a second light, a light guiding means for guiding the first light emitted from the lamp and the second light emitted through the lamp holder to emit a third light, and a receiving container for receiving the lamp assembly and the light guiding means.
In further aspect, an LCD apparatus comprises a backlight unit comprising a lamp assembly having a lamp holder for receiving one end of a lamp which emits a light in response to an external electric power, the lamp holder emitting a portion of the light emitted from the lamp, a light guiding means for guiding the light emitted from the lamp and the lamp holder, and a receiving container for receiving the lamp assembly and the light guiding means, and a display unit for displaying an image in response to the light emitted from the backlight assembly.
According to the lamp assembly, backlight assembly and LCD apparatus having the same, the dark portions generated by the lamp holder may be removed and the brightness of the light may be enhanced by using a transparent or semi-transparent lamp holder that receives both ends of the lamp.